In a rigid disk storage device, one or more rotating disks, such as magnetic disks (sometimes referred to as “platters”), are used to store information. Rigid disk storage devices typically include a frame to provide attachment points and orientation for other components, and a spindle motor mounted on the frame for rotating the disk. A read/write element is formed on a “head slider” for reading and writing data from and to the disk surface. The head slider typically is supported and oriented relative to the disk by a head suspension assembly, providing both the force and compliance necessary for proper head slider operation. The head suspension assembly typically comprises a loadbeam and flexure, which can be attached to, or integrally formed with, the loadbeam. The head suspension assembly typically is attached to an actuator arm or E-block, which is in turn attached to an actuator. As the disk in the storage device rotates beneath the head slider and head suspension, the air above the disk also rotates, thereby creating an air bearing which acts with an aerodynamic design of the head slider to create a lift force on the head slider. The balance between the lift force and load force exerted by the head suspension substantially determines the distance, or “flying height” between the read/write head and the surface of the disk.
The trend in the evolution of dynamic rigid disk storage devices is toward higher data storage density, higher read/write speed, and smaller device size. To achieve higher data storage density, the read/write head must be sufficiently close to the disk surface. That is, the flying height must be sufficiently small. For example, for a data density of about 7.8 Gigabytes/cm2 or greater on a magnetic hard drive, the flying height of the slider is typically on the order of 10 nm or less.
To consistently attain such small flying heights, the performance parameters of the suspension assembly must be controlled carefully. One critical parameter is the static attitude, which is the angular attitude of the slider's read/write surface facing the disk as mounted relative to disk surface. If the static attitude is set improperly, undesired slider pitch or roll may result. To ensure that the performance parameters are properly set, not only is the manufacturing process of the various components of the head suspension carefully controlled, at least some of the parameters are also measured and adjusted when necessary after the head suspension is assembled. Adjustment of certain parameters, including the static attitude, requires external post-assembly access to certain components, such as the flexure.
In certain types of head suspensions, a portion of the loadbeam overhangs the flexure such that at least a substantial length of the flexure is positioned between the disk surface and the loadbeam. Such extension in the loadbeam has several applications. As one example, there can be range limiters formed on a loadbeam and/or the flexure extending from the loadbeam to prevent the flexure from being deformed beyond a certain state. As another example, the loadbeam can extend over the entire length of the flexure and include a head lifter tab at the tip of the loadbeam for parking the slider head. In these types of head suspensions, the flexure is commonly made with portions wider than the overhanging portion or portions of the loadbeam so that those wider portions of the flexure are accessible from the loadbeam side of the flexure. Certain performance parameters can thus be adjusted by altering the characteristics of the accessible portions of the flexure.
Such widening of flexure, however, is undesirable for maximizing the overall storage capacity density of the storage device, i.e., the storage capacity per unit volume of the device. A wider flexure increases the minimum distance the slider head can approach the hub of the disk, thus making a greater portion of the disk near the hub unavailable for data storage and thus wasting device volume. Additional undesirable effects of such widening of the flexure include the lowered natural frequencies of the flexure and increased wind induced off-track that can be associated with it.
There is thus a need for a head suspension with improved characteristics, with better utilization of device space while maintaining the ability to adjust performance parameters of the head suspension.